1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to a digital rights management (DRM), and more particularly, to a DRM method and apparatus which can support different DRMs and use various digital content.
2. Description of the Related Art
Recently digital rights management (hereinafter referred to as “DRM”) has been researched actively and commercial services using DRM have already been implemented or will be implemented. DRM is a technical concept to protect digital content that can be readily copied and distributed without permission.
Some efforts have been made to protect digital content. Conventionally, digital content protection has concentrated on preventing those without permission from accessing digital content. Specifically, only those people who have paid fees are permitted to access the digital content, and persons who have not paid the charges are denied access the digital content. However, the digital content can be readily copied, reused, processed and distributed to third parties according to the characteristics of the digital data. Accordingly, when a person who has paid the fees accesses the digital content and intentionally distributes it to a third party, the third party can use the digital content without paying the fees, which has produced a number of problems.
In order to solve these problems, in DRM, the digital content is encrypted and distributed, and a specified license called a rights object (RO) is needed to use the encrypted digital content.
A rights object stored in a host device can be moved or copied to a portable storage device. Portable storage devices, such as extreme Digital (XD) cards and multimedia cards, can be easily inserted into or removed from host devices such as mobile phones, computers and digital cameras. Portable storage devices go beyond the bounds of conventional hard disks and compact disks. That is, portable storage devices cannot only store data but also perform computing functions such as data control and operation. Recently, new-concept portable storage devices that combine a security function with the existing portable storage devices are being developed. The new-concept portable storage devices can protect digital copyright by securing the storage and transmission or reception of digital content. Accordingly, DRM can be applied to the relationship between a portable storage device and a host device. That is, a rights object can be stored in a portable storage device, and a host device can play back encrypted content using the rights object stored in the portable storage device.